Not checking in with London ATC
Sometimes it is just not possible. I know you are busy people but please tell me why there seems to be a competition between London controllers (mainly women) to see who can make the longest ATC transmission without a break or breath. I think I counted 20 different calls once and I just gave up and sure enough the 21st call was "is XXX 125 on frequency" made with a slightly annoyed tone of voice.